(I posted this same general question here on StackOverflow thinking it had something to do with my emacs configuration, but after following a comment there, I think it is exclusive to urxvt)

My problem is that, under seemingly random circumstances, the point will be hidden by a large block of the same color as the point. What is interesting about it is that it does behave as the point/console cursor does when I unfocus the terminal window, in that the normally fully-opaque box becomes hollow. So, essentially, the point will suddenly appear wider than normal.

I use emacs in urxvt only, and I can currently replicate the behavior by pressing space around 5-6 times, at which point the point appears to be 2 wide. This point-widening does not occur when I am in tmux or use lxterminal